X f ferdinand beauis



2 SHEETS-SHEET 1.

PATENTED JAN. 26, 1904.

I f T51 f i 1257a} P. BRAUN. WIRELESS ELECTRIC TRANSMISSION OF SIGNALS OVER SURFACES. APPLICATION FILED FBB.6, 1899.

My i I No. 750,429. N0 MQDEL.

25 s. mmxm ENERGY.

I 7 No. 750,429. PATENTED JAN. 26, 1904.

I E. BRAUN.

WIRELESS ELECTRIC TRANSMISSION OF SIGNALS OVER SURFACES.

APPLICATION FILED FEB. 6. 1899. NO MODEL. 2 SHEETS-SHEET 2.

.. I "o i gf p o known to electricians, that when alternating 1 dent of Strassburg, Alsace, German Empire,

V UNITED STATES Patented January 26, 1904.

PaTENT OFFICE.

WIRELESS ELECTRIC TRANSMISSQ 0F S.lGNALS OVER SURFACES.

SPECIFICATION forming part of Letters Patent No. 750,429, dated January 26, 1904.

Application filed February 6,1899. ScrialiNo. 704,604. (No model.) i

To all whom it Duty concern:

Be it known that I, FERDINAND BRAUN, a sub ect of theGerman Em eror, and a resihave invented a newand useful ,lVireless Electric Transmission of Signals Over Surfaces, of which the following is a specification,

My invention relates to the transmission of electric signals without connecting-wires.

The accompanying c lrawings illustrate diagrammatically preferredapparatus for carrying out the invention.

. Figure-1 shows a form of the transmitting apparatus. Fig. Q's-hows an apparatus-having induction-coils forming ati'ansformer. Figs. 3, a; and 5'showmodificatioi s. hereinafter explained, and Fig. (5 shows-the general arrange ment of the electrical connections of the transmitting and receivil g aapparatus Hitherto the transmission ofgel'ectricgsig- "nals as above mentioned,- usually termed wireless telegraphy, beenbased on the. propagation of electric waves-in space, and

various difiiculties have been'e-ncountered which haye prevented such methods being satisfactory According to my invention Iavoid these difficulties by utilizing thegsurfacesiof conductingrbodiesas a medium for the transmission of-the electric waves.

My invention is based on the fact, now well currents of high frequency are supplied to cylindrical conductors the outer surface of the conductor is the important factor in transmitting the energy, and the inner portions of the conductor are of very little use. This fact, which is true for conducting bodies,is also true for semiconductors, such as water and earth,

' as experiments on. a" large scale have concluisiyely shown.

According to my invention I take advantage of the tendency above mentioned for electriccurrent waves to press toward the outer surface of a conductor or semiconductor by ap-- plying to two plates buried in the earth at a short distance apart an alternating current of very high intensity and frequency- The lines of .low of the current from one plate to the other will no longer take the shortest. pathbut will pass from their sources in large arcs.

' and a a the spark-gaps in air or in oil.

ma-y be effected in the usual manner.

en i i-plates inserted at points of dlfferent po- I p i,

covering a considerable area. Within this area the current Vibrations may be collected and utilized to give signals by devices of any suitable description. The application of the alternating current to the earth-plates can be arranged in various ways-for example, currents of high frequency may be created in a complete system by means of condensers, for instance, and these currents can be then supplied to the wires which lead to the earthplates, or by means of rotary machines a very high frequency may he forcibly obtained which is independent of the self-induction and capacity of the earth-plates. With these details my present invention is not particularly concerned, as-various methods of supply may be adopted. In order, however, that my in-- induction-coil or a Holzs influence-machine,

P P are the earth-plates; This is the well-known apparatus used by Hertz, in which, as shown, for example, in Fig. 1, condensers may be interposed between the two pairs of balls. In Fig. 2 the earth-plates are connected with the spark-circuit through the medium of an induction-coil.

Figs. 3 and 4 show condensers joined in cascade, in Fig. 3 with primary coils interposed between the successive condensers, so as to act inductively on the circuit containing the earthplates P P, and in Fig. 4 without any induction-coil.

Fig. 5 shows another arrangement in which two spark-gaps are provided in circuit with the earthplates, in which the combined action of capacity and induction is used. The evident purpose of this arrangement is to retard the vibrations whose frequency depends in a well-known manner upon the product L0; in which L signifies the self-induction, C the capacity. Various other arrangements'of apparatus may be used.

The collection of the electric disturbations Two tential and connected with each other by means of wire will serve for the purpose, a coherer being inserted in its circuit as a delicate receiving element.

A diagrammatical illustration of the manner of carrying out both the transmitting and receiving stations is shown in Fig. 6. R means a Ruhmkorif induction apparatus, with the airgap a. C C are the condensers; P P, the earth-plates, as mentioned above. are parts of the transmitting-station. In the, receiving-station P I are the collecting earth plates; F, the well-known coherer or the like. M is a Morse apparatus with its battery I; and earth-plate P'i. In the moment of action a local circuit will be closed, comprising battery, Morse apparatus, coherer, and earth-plates, as the line coming from the battery is connected to the middle of the coherer. All these connections may be varied in the manner now well known by electricians well up in what has been done already in the line of wireless telegraphy;

The advantages of my improved system are, first, the suppressiop o f aerial wires, with all their attendant evils and inconveniences; second, that the energy expended remaining upon the surface of the conductor it follows that the energy will not be diminished according to the square of the distance, as is the case when radiating freely through the space, but in a much less degree, being limited to surface extension; third, an uneven or a wooded surface will present no obstacle to the transmission.

What I claim, and desire to secure by Letters Patent of the United States, is-

All theseq 1. The method of transmitting signals elecplying currents by means of an oscillation-,

circuit containing a condenser and a sparkgap to earth-plates connected to opposite poles of the transmitting apparatus, and collecting the impulses by earth-plates at the receivingstation connected to opposite poles of the coll'ecting apparatus, substantially as described.

2. The method of transmitting signals elecfiically from one station to another without the use of connecting-wires, consisting in supplying currents by means of an oscillationcircuit containing a condenser, a spark-gap and an induction-coil to earth-plates connected to opposite poles of the transmitting apparatus, and collecting the impulses by earthplates at the receiving-station connected to opposite poles of the collecting apparatus, substantially as described.

3. The method of transmitting signals electrically from one station to another without the use of connecting-wires, consisting in supplying currents produced by an oscillationcircuit containing a condenser, a spark-gap and the primary coil'of a transformer to earthplates connected to opposite poles of the secondary coil of said transformer, and collecting the impulses by earth-plates at the receivingstation connected to opposite poles of the collecting apparatus, substantially as described.

In testimony whereot'Ihave hereunto set my hand in presence of two subscribing witnesses.

FERDINAND BRAUN.

Witnesses:

FRITZ Nrnss, MAX ADLER. 

